Alfuzosin is a selective alpha-1 adrenoceptor antagonist that belongs to the chemical class of 4-amino-6,7-dimethoxy-quinazol-2-yl-alkylene diamines. It is commercially available as alfuzosin hydrochloride and marketed as Uroxatral® tablet dosage form. Alfuzosin has a short half-life and shows the characteristic of being absorbed preferentially in the upper part of the gastrointestinal tract and, in particular, being absorbed in the duodenum and the jejunum. Sustained release compositions of alfuzosin provide various advantages over conventional multiple dosing including better patient compliance, reduced fluctuations of plasma drug levels, and reduced toxicity.
Alfuzosin is marketed for the treatment of benign prostatic hyperplasia and, more specifically, for the treatment of the symptoms associated with benign prostatic hyperplasia. Alfuzosin is indicated for the treatment of moderate to severe symptoms of benign prostatic hyperplasia.
U.S. Pat. No. 6,149,940 discloses a preparation of alfuzosin 10 mg once daily composition for oral delivery using a Geomatrix technology. The three-layer tablet described in the patent consists of a hydrophilic active matrix core containing alfuzosin hydrochloride in a single layer supported by two inert, non-functional layers (one swellable layer and one erodible layer) whose functions are to control the hydration and swelling rate of the core, and thereby slow down and linearize the dissolution of the drug. When the tablet comes into contact with gastric juices, it increases considerably in volume and thus remains in the stomach for a longer time. In this manner, most of the drug is absorbed in a controlled manner in the portion of the gastrointestinal tract having the highest capacity for absorption. The alfuzosin is released in zero order from the dosage form developed using this technology.
U.S. Pat. No. 5,589,190 discloses a pharmaceutical composition that includes an alfuzosin core. The core is coated with a coating whose dissolution is pH dependent, which thereby enables the release of alfuzosin to be modulated over the entire length of the digestive tract.
EP 700,285 discloses drug delivery compositions of alpha adrenoceptor blocking agents that have a biphasic drug release profile.
U.S. Pat. No. 4,259,314 discloses a dry pharmaceutical formulation containing a therapeutic agent and a dry carrier that includes hydroxypropyl methylcellulose and hydroxypropyl cellulose.
International (PCT) Publication WO2004037228 discloses sustained release dosage forms of alfuzosin or salts thereof having single functional layers and optionally one or more non-functional layers along with one or more release retarding ingredients.
Several other pharmaceutical compositions comprising alfuzosin have been reported for example, in U.S. Pat. No. 5,589,190; U.S. application Nos. 20060062846; 20060062845; 20060147530; European Patent Nos. 938318(B1); 673650(B1); 1556014(A1) and International (PCT) Publication Nos. WO2004037228 and W02006094736.